William:

You didn't say what model van you have and whether you have AC. The fan
not coming on is an indication that the ($6) temperature switch screwed
in the radiator housing (driver's side) is fouled and needs to be
replaced. When I replaced this with a new radiator, my fan comes on more
frequently like it's supposed to - allowing me to remove the manual
radiator fan switch (which I fried by leaving it on too long!).

For the idling problems, consider the ISV (idle stabilizer valve) -
remove it and clean thoroughly with brake cleaner. This works for me
when my idle varies as you describe.

Another option could be the ICU (idle control unit) - the electronic
gizmo mounted behind the right rear taillight. This is supposed to
up-the-idle during specific circumstances (AC on, cold engine, boost to
power steering when turning the wheel all the way to one side).

I don't know much about the AFM - I've decided not to break into mine
and fidget with it.

Good luck & let us know what you find.

In *V*anagon *W*esty love, light, & laughter,
Jay
Springfield MO
'87 Westy
343k miles on original transmission

Greenamyer, William L wrote:
> Very interesting thing happened driving home from work yesterday.  My
> van has been hunting (change in idle speed) at idle for a while now and
> I have not had time to address it.  I also have a manual radiator fan
> switch to use in traffic or when I climb the Cajon pass (6 degree grade)
> when the temperature is well over 100 degrees.  I never noticed before
> when the van can be hunting and as soon as I turned on the radiator fan,
> the hunting stopped and didn't not come back until the fan was turned
> off.  The fan draws a fair amount of current in the high setting and I
> am guessing that it changes the load on the engine just enough to
> correct the hunting problem.  Doesn't tell me which way to adjust the
> AFM dial or screw but it does tell me that the overall AFM setting is
> not correct for idle.  I welcome comments.
>
> William
>
>